摘要:
An optical compensator for use in an optical scanning device for scanning a first optical record carrier (3′) having an information layer (2′) at a first information layer depth d and a second optical record carrier (3″) having an information layer (2″) at a second, different information layer depth d2. The scanning of the first and second optical record carrier is effected using a scanning spot (16) formed on the information layer by a first radiation beam having a first wavelength and a second radiation beam having a second, different wavelength respectively. The optical compensator includes a substantially circular phase structure having an annular zone arranged in the path of the first radiation beam and the second radiation beam. The annular zone is adapted for imparting a wavefront modification to said first radiation beam causing destructive interference over the area of the scanning spot (16) for radiation incident on said annular zone; and a wavefront modification to said second radiation beam for compensating spherical aberration. A further aspect of the present invention relates to an optical element for defining the numerical aperture of a radiation beam. The optical compensator or optical element can be used for a two- or three-wavelength system. The invention also discloses an optical scanning head, and an optical scanning device using the optical compensator. The invention also relates to an optical scanning head and an optical scanning device.
摘要:
The invention relates to a method of and a device for compensating tilt of an optical or magneto-optical disc (1) exhibiting unknown tilt when placed in an apparatus for reading and/or writing data from and/or onto the optical or magneto-optical disc. A holographic optical element (23) containing a plurality of holograms each defining a phase profile able to compensate at least a specific coma amount is placed in a light path of an optical read/write unit (4) of the apparatus. The amount of tilt of the disc or coma introduced by the tilt is detected (14, 21), and a hologram defining a phase profile corresponding to the detected amount of tilt or coma is selected and accessed among the plurality of holograms of the holographic optical element for compensating the detected amount of tilt or coma. The invention applies to any type of optical data carrier such as so-called LD, CD, R-CD, DVD, DVD+R, DVD+RW, DVD-RW, DVR (Blue Ray).
摘要:
In an optical scanning device (10) capable of scanning an information plane of an optical record carrier (5) of different types such as BD, DVD and CD, the diameter of the radiation spot on the detector (7) is dependent on the numerical aperture of the objective system (4) that is used for scanning the record carrier An optimal design of the optical detection system for scanning a BD, result in a small radiation spot for the other types such as DVD and CD. By implementing an optical element (13) that increases the diameter of the radiation spot in the situation a DVD or CD is scanned, the influence of stray light is reduced and the tracking signals are improved
摘要:
An optical scanning device (1) includes a radiation source (7), a detector (23) and a beam splitter (9). The radiation source (7) provides an incident radiation beam (4, 20) along a first optical path (19a) for scanning an information layer (2) of an optical record carrier (3). The detector (23) detects at least a portion of the radiation beam (22) reflected from the optical record carrier (3). The beam splitter (9) transmits the incident radiation beam (4) received from the radiation source along the first optical path (19a) towards the optical record carrier. The beam splitter (9) also transmits the reflected beam (22) received from the optical record carrier (3) along a second, different optical path (19b) towards the detector. The optical scanning device further includes a beam-deflecting element (30; 130; 230; 330; 630; 830; 930) positioned on the second optical path (19b) between the beam splitter (9) and the detector (23). The beam-deflecting element (30; 130; 230; 330; 630; 830; 930) is arranged to controllably deflect the path of the reflected radiation beam (22) for adjusting the lateral position of said reflected radiation beam incident upon the detector (23) over a predetermined range.
摘要:
A beam-shaping element includes a cavity, a first fluid and a second fluid having different indices of refraction. An optical axis extends through the cavity. The cavity has at least one curved surface extending transverse the optical axis. At least one pump is arranged to pump the fluids between a first configuration in which the first fluid occupies the cavity, and a second configuration in which the second fluid occupies the cavity.
摘要:
An elongated luminaire for illuminating objects in front of the luminaire, comprising a plurality of side emitting LEDs (1) in only one straight array mounted on an elongated base plate (2). The base plate (2) carries two elongated reflectors (3) extending on either side of the array of LEDs (1) and parallel to the array of LEDs (1). Each reflector (3) has a reflecting surface (4) directed towards the array of LEDs (1).
摘要:
A collimating module is presented. The collimating module comprises a rounded light entry side and a rectangular light exit side. A collimating device is also presented, and a method for providing collimated light. The collimating device comprises a first collimator having a light entry side and a light exit side, a scattering component having a light entry surface arranged adjacent to said light exit side, and a light exit surface. The collimating device further comprises a collimating module having a light entry side arranged adjacent to said light exit surface.
摘要:
An optical scanning device for scanning optical record carriers, the optical record carriers including a first optical record carrier, a second optical record carrier and a third optical record carrier, the scanning device including a radiation source system (7) for producing first, second and third radiation beams for scanning said first, second and third record carriers, respectively, in first, second and third scanning modes, said first, second and third radiation beams having different predetermined wavelengths, the scanning device comprising an objective lens and an optical compensator, the optical compensator having a non-periodic phase structure through which each of said first, second and third radiation beams are arranged to pass, said non-periodic phase structure including a plurality of stepped annular zones separated by steps, the zones forming a non-periodic radial pattern, the stepped annular zones introducing first, second and third different wavefront modifications into at least part of the first, second and third radiation beams, respectively, characterized in that said objective lens is arranged to apply a focus offset when scanning said first record carrier, which focus offset is arranged to provide a phase modification which, in combination with said optical compensator, compensates spherical aberration in the first radiation beam.
摘要:
A property of a fluid is determined spectroscopically, such as for the purposes of in vivo blood analysis. First the position of a volume of interest through which the fluid flows is determined by an optical detection step by making use of an objective. Preferably the optical detection step is an imaging step. Next the objective is moved to bring the focal point of the objective into coincidence with the volume of interest. In this position an optical spectroscopic step is performed. This has the advantage that the measurement beam for performing the optical spectroscopy travels along the optical axis for optimum efficiency.
摘要:
This invention relates to an optical scanning device for scanning an optical record carrier and detecting a tilt characteristic of the optical record carrier during scanning. The device includes a redirecting structure (26) arranged on an objective lens (10) to redirect a part of a radiation beam, when travelling towards the record carrier, differently to a main part of the radiation beam. The redirected beam part follows a path which is different to that of a path followed by the main beam part, towards a position sensitive detector in a detection system (16).